#app {
    width: 400px;
    border: 4px solid green;
    background: #fff;
    padding: 1em 1em 1em;
    margin: 20px auto;
    box-shadow: 3px 3px 3px rgba(0, 0, 0, 0.5);
    border-radius: 1em;

    h3 {
        text-align: center;
    }
}

body {
    background: rgb(217, 223, 223);
}

.panel {
    .title {
        display: flex;
        justify-content: space-between;
        align-items: center;
        border: 1px solid #ccc;
        padding: 0 1em;

        h4 {
            margin: 0;
            line-height: 2;
        }

        .btn {
            cursor: pointer;
        }

    }

    .container {
        border: 1px solid rgb(231, 248, 231);
        padding: 0 1em;
        /* border-top-color: transparent; */
    }

}